All Science Fair Projects

Over 1000 FREE Science Fair Project Ideas!

Bacteria in your toothbrushFeatured science projectScience project video


The hypothesis that  toothbrushes kept in Listerine solution  have the least amount of bacteria, is proven to be true.

Proper  tooth  brushing techniques will help to get rid of plaque and bacteria that are responsible for tooth decay and gum disease. Using toothpaste which contains fluoride helps to strengthen one's teeth against decay. It also helps to remove stains from the teeth and gives us clean, fresh breath.

Also consider

To improve the reliability and accuracy of our results, a larger sample of participants should be used.

This science fair project may be repeated, this time, with  taking a swab sample from the mouth after gargling with water, gargling with mouth wash and gargling with Listerine and comparing the bacteria content.

Modify the science project experiment, using saltwater, lime juice and sterilized water.


Mouth bacteria, it’s a jungle in there -

Toothpaste -

See our all-time most popular science projects
Search science fair projects Browse science fair projects
popular science fair projects
Complexity level:
Project cost ($):
Time required:
5 days to prepare, 5 days for science fair project
Material availability:
Easily found
Safety concerns:

Basic safety requirements